xref: /qemu/target/s390x/tcg/vec_fpu_helper.c (revision 863b9507a61bb4f5707de0dadca829945c149e6e)
1 /*
2  * QEMU TCG support -- s390x vector floating point instruction support
3  *
4  * Copyright (C) 2019 Red Hat Inc
5  *
6  * Authors:
7  *   David Hildenbrand <david@redhat.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
10  * See the COPYING file in the top-level directory.
11  */
12 #include "qemu/osdep.h"
13 #include "qemu-common.h"
14 #include "cpu.h"
15 #include "internal.h"
16 #include "vec.h"
17 #include "tcg_s390x.h"
18 #include "tcg/tcg-gvec-desc.h"
19 #include "exec/exec-all.h"
20 #include "exec/helper-proto.h"
21 #include "fpu/softfloat.h"
22 
23 #define VIC_INVALID         0x1
24 #define VIC_DIVBYZERO       0x2
25 #define VIC_OVERFLOW        0x3
26 #define VIC_UNDERFLOW       0x4
27 #define VIC_INEXACT         0x5
28 
29 /* returns the VEX. If the VEX is 0, there is no trap */
30 static uint8_t check_ieee_exc(CPUS390XState *env, uint8_t enr, bool XxC,
31                               uint8_t *vec_exc)
32 {
33     uint8_t vece_exc = 0, trap_exc;
34     unsigned qemu_exc;
35 
36     /* Retrieve and clear the softfloat exceptions */
37     qemu_exc = env->fpu_status.float_exception_flags;
38     if (qemu_exc == 0) {
39         return 0;
40     }
41     env->fpu_status.float_exception_flags = 0;
42 
43     vece_exc = s390_softfloat_exc_to_ieee(qemu_exc);
44 
45     /* Add them to the vector-wide s390x exception bits */
46     *vec_exc |= vece_exc;
47 
48     /* Check for traps and construct the VXC */
49     trap_exc = vece_exc & env->fpc >> 24;
50     if (trap_exc) {
51         if (trap_exc & S390_IEEE_MASK_INVALID) {
52             return enr << 4 | VIC_INVALID;
53         } else if (trap_exc & S390_IEEE_MASK_DIVBYZERO) {
54             return enr << 4 | VIC_DIVBYZERO;
55         } else if (trap_exc & S390_IEEE_MASK_OVERFLOW) {
56             return enr << 4 | VIC_OVERFLOW;
57         } else if (trap_exc & S390_IEEE_MASK_UNDERFLOW) {
58             return enr << 4 | VIC_UNDERFLOW;
59         } else if (!XxC) {
60             g_assert(trap_exc & S390_IEEE_MASK_INEXACT);
61             /* inexact has lowest priority on traps */
62             return enr << 4 | VIC_INEXACT;
63         }
64     }
65     return 0;
66 }
67 
68 static void handle_ieee_exc(CPUS390XState *env, uint8_t vxc, uint8_t vec_exc,
69                             uintptr_t retaddr)
70 {
71     if (vxc) {
72         /* on traps, the fpc flags are not updated, instruction is suppressed */
73         tcg_s390_vector_exception(env, vxc, retaddr);
74     }
75     if (vec_exc) {
76         /* indicate exceptions for all elements combined */
77         env->fpc |= vec_exc << 16;
78     }
79 }
80 
81 static float64 s390_vec_read_float64(const S390Vector *v, uint8_t enr)
82 {
83     return make_float64(s390_vec_read_element64(v, enr));
84 }
85 
86 static void s390_vec_write_float64(S390Vector *v, uint8_t enr, float64 data)
87 {
88     return s390_vec_write_element64(v, enr, data);
89 }
90 
91 typedef uint64_t (*vop64_2_fn)(uint64_t a, float_status *s);
92 static void vop64_2(S390Vector *v1, const S390Vector *v2, CPUS390XState *env,
93                     bool s, bool XxC, uint8_t erm, vop64_2_fn fn,
94                     uintptr_t retaddr)
95 {
96     uint8_t vxc, vec_exc = 0;
97     S390Vector tmp = {};
98     int i, old_mode;
99 
100     old_mode = s390_swap_bfp_rounding_mode(env, erm);
101     for (i = 0; i < 2; i++) {
102         const uint64_t a = s390_vec_read_element64(v2, i);
103 
104         s390_vec_write_element64(&tmp, i, fn(a, &env->fpu_status));
105         vxc = check_ieee_exc(env, i, XxC, &vec_exc);
106         if (s || vxc) {
107             break;
108         }
109     }
110     s390_restore_bfp_rounding_mode(env, old_mode);
111     handle_ieee_exc(env, vxc, vec_exc, retaddr);
112     *v1 = tmp;
113 }
114 
115 typedef float64 (*vop64_3_fn)(float64 a, float64 b, float_status *s);
116 static void vop64_3(S390Vector *v1, const S390Vector *v2, const S390Vector *v3,
117                     CPUS390XState *env, bool s, vop64_3_fn fn,
118                     uintptr_t retaddr)
119 {
120     uint8_t vxc, vec_exc = 0;
121     S390Vector tmp = {};
122     int i;
123 
124     for (i = 0; i < 2; i++) {
125         const float64 a = s390_vec_read_float64(v2, i);
126         const float64 b = s390_vec_read_float64(v3, i);
127 
128         s390_vec_write_float64(&tmp, i, fn(a, b, &env->fpu_status));
129         vxc = check_ieee_exc(env, i, false, &vec_exc);
130         if (s || vxc) {
131             break;
132         }
133     }
134     handle_ieee_exc(env, vxc, vec_exc, retaddr);
135     *v1 = tmp;
136 }
137 
138 #define DEF_GVEC_VOP3(NAME, OP)                                                \
139 void HELPER(gvec_##NAME##64)(void *v1, const void *v2, const void *v3,         \
140                              CPUS390XState *env, uint32_t desc)                \
141 {                                                                              \
142     const bool se = extract32(simd_data(desc), 3, 1);                          \
143                                                                                \
144     vop64_3(v1, v2, v3, env, se, float64_##OP, GETPC());                       \
145 }
146 
147 DEF_GVEC_VOP3(vfa, add)
148 DEF_GVEC_VOP3(vfs, sub)
149 DEF_GVEC_VOP3(vfd, div)
150 DEF_GVEC_VOP3(vfm, mul)
151 
152 static int wfc64(const S390Vector *v1, const S390Vector *v2,
153                  CPUS390XState *env, bool signal, uintptr_t retaddr)
154 {
155     /* only the zero-indexed elements are compared */
156     const float64 a = s390_vec_read_element64(v1, 0);
157     const float64 b = s390_vec_read_element64(v2, 0);
158     uint8_t vxc, vec_exc = 0;
159     int cmp;
160 
161     if (signal) {
162         cmp = float64_compare(a, b, &env->fpu_status);
163     } else {
164         cmp = float64_compare_quiet(a, b, &env->fpu_status);
165     }
166     vxc = check_ieee_exc(env, 0, false, &vec_exc);
167     handle_ieee_exc(env, vxc, vec_exc, retaddr);
168 
169     return float_comp_to_cc(env, cmp);
170 }
171 
172 void HELPER(gvec_wfc64)(const void *v1, const void *v2, CPUS390XState *env,
173                         uint32_t desc)
174 {
175     env->cc_op = wfc64(v1, v2, env, false, GETPC());
176 }
177 
178 void HELPER(gvec_wfk64)(const void *v1, const void *v2, CPUS390XState *env,
179                         uint32_t desc)
180 {
181     env->cc_op = wfc64(v1, v2, env, true, GETPC());
182 }
183 
184 typedef bool (*vfc64_fn)(float64 a, float64 b, float_status *status);
185 static int vfc64(S390Vector *v1, const S390Vector *v2, const S390Vector *v3,
186                  CPUS390XState *env, bool s, vfc64_fn fn, uintptr_t retaddr)
187 {
188     uint8_t vxc, vec_exc = 0;
189     S390Vector tmp = {};
190     int match = 0;
191     int i;
192 
193     for (i = 0; i < 2; i++) {
194         const float64 a = s390_vec_read_element64(v2, i);
195         const float64 b = s390_vec_read_element64(v3, i);
196 
197         /* swap the order of the parameters, so we can use existing functions */
198         if (fn(b, a, &env->fpu_status)) {
199             match++;
200             s390_vec_write_element64(&tmp, i, -1ull);
201         }
202         vxc = check_ieee_exc(env, i, false, &vec_exc);
203         if (s || vxc) {
204             break;
205         }
206     }
207 
208     handle_ieee_exc(env, vxc, vec_exc, retaddr);
209     *v1 = tmp;
210     if (match) {
211         return s || match == 2 ? 0 : 1;
212     }
213     return 3;
214 }
215 
216 void HELPER(gvec_vfce64)(void *v1, const void *v2, const void *v3,
217                          CPUS390XState *env, uint32_t desc)
218 {
219     vfc64(v1, v2, v3, env, false, float64_eq_quiet, GETPC());
220 }
221 
222 void HELPER(gvec_vfce64s)(void *v1, const void *v2, const void *v3,
223                           CPUS390XState *env, uint32_t desc)
224 {
225     vfc64(v1, v2, v3, env, true, float64_eq_quiet, GETPC());
226 }
227 
228 void HELPER(gvec_vfce64_cc)(void *v1, const void *v2, const void *v3,
229                             CPUS390XState *env, uint32_t desc)
230 {
231     env->cc_op = vfc64(v1, v2, v3, env, false, float64_eq_quiet, GETPC());
232 }
233 
234 void HELPER(gvec_vfce64s_cc)(void *v1, const void *v2, const void *v3,
235                             CPUS390XState *env, uint32_t desc)
236 {
237     env->cc_op = vfc64(v1, v2, v3, env, true, float64_eq_quiet, GETPC());
238 }
239 
240 void HELPER(gvec_vfch64)(void *v1, const void *v2, const void *v3,
241                          CPUS390XState *env, uint32_t desc)
242 {
243     vfc64(v1, v2, v3, env, false, float64_lt_quiet, GETPC());
244 }
245 
246 void HELPER(gvec_vfch64s)(void *v1, const void *v2, const void *v3,
247                           CPUS390XState *env, uint32_t desc)
248 {
249     vfc64(v1, v2, v3, env, true, float64_lt_quiet, GETPC());
250 }
251 
252 void HELPER(gvec_vfch64_cc)(void *v1, const void *v2, const void *v3,
253                             CPUS390XState *env, uint32_t desc)
254 {
255     env->cc_op = vfc64(v1, v2, v3, env, false, float64_lt_quiet, GETPC());
256 }
257 
258 void HELPER(gvec_vfch64s_cc)(void *v1, const void *v2, const void *v3,
259                              CPUS390XState *env, uint32_t desc)
260 {
261     env->cc_op = vfc64(v1, v2, v3, env, true, float64_lt_quiet, GETPC());
262 }
263 
264 void HELPER(gvec_vfche64)(void *v1, const void *v2, const void *v3,
265                           CPUS390XState *env, uint32_t desc)
266 {
267     vfc64(v1, v2, v3, env, false, float64_le_quiet, GETPC());
268 }
269 
270 void HELPER(gvec_vfche64s)(void *v1, const void *v2, const void *v3,
271                            CPUS390XState *env, uint32_t desc)
272 {
273     vfc64(v1, v2, v3, env, true, float64_le_quiet, GETPC());
274 }
275 
276 void HELPER(gvec_vfche64_cc)(void *v1, const void *v2, const void *v3,
277                              CPUS390XState *env, uint32_t desc)
278 {
279     env->cc_op = vfc64(v1, v2, v3, env, false, float64_le_quiet, GETPC());
280 }
281 
282 void HELPER(gvec_vfche64s_cc)(void *v1, const void *v2, const void *v3,
283                               CPUS390XState *env, uint32_t desc)
284 {
285     env->cc_op = vfc64(v1, v2, v3, env, true, float64_le_quiet, GETPC());
286 }
287 
288 static uint64_t vcdg64(uint64_t a, float_status *s)
289 {
290     return int64_to_float64(a, s);
291 }
292 
293 void HELPER(gvec_vcdg64)(void *v1, const void *v2, CPUS390XState *env,
294                          uint32_t desc)
295 {
296     const uint8_t erm = extract32(simd_data(desc), 4, 4);
297     const bool XxC = extract32(simd_data(desc), 2, 1);
298 
299     vop64_2(v1, v2, env, false, XxC, erm, vcdg64, GETPC());
300 }
301 
302 void HELPER(gvec_vcdg64s)(void *v1, const void *v2, CPUS390XState *env,
303                           uint32_t desc)
304 {
305     const uint8_t erm = extract32(simd_data(desc), 4, 4);
306     const bool XxC = extract32(simd_data(desc), 2, 1);
307 
308     vop64_2(v1, v2, env, true, XxC, erm, vcdg64, GETPC());
309 }
310 
311 static uint64_t vcdlg64(uint64_t a, float_status *s)
312 {
313     return uint64_to_float64(a, s);
314 }
315 
316 void HELPER(gvec_vcdlg64)(void *v1, const void *v2, CPUS390XState *env,
317                           uint32_t desc)
318 {
319     const uint8_t erm = extract32(simd_data(desc), 4, 4);
320     const bool XxC = extract32(simd_data(desc), 2, 1);
321 
322     vop64_2(v1, v2, env, false, XxC, erm, vcdlg64, GETPC());
323 }
324 
325 void HELPER(gvec_vcdlg64s)(void *v1, const void *v2, CPUS390XState *env,
326                            uint32_t desc)
327 {
328     const uint8_t erm = extract32(simd_data(desc), 4, 4);
329     const bool XxC = extract32(simd_data(desc), 2, 1);
330 
331     vop64_2(v1, v2, env, true, XxC, erm, vcdlg64, GETPC());
332 }
333 
334 static uint64_t vcgd64(uint64_t a, float_status *s)
335 {
336     const uint64_t tmp = float64_to_int64(a, s);
337 
338     return float64_is_any_nan(a) ? INT64_MIN : tmp;
339 }
340 
341 void HELPER(gvec_vcgd64)(void *v1, const void *v2, CPUS390XState *env,
342                          uint32_t desc)
343 {
344     const uint8_t erm = extract32(simd_data(desc), 4, 4);
345     const bool XxC = extract32(simd_data(desc), 2, 1);
346 
347     vop64_2(v1, v2, env, false, XxC, erm, vcgd64, GETPC());
348 }
349 
350 void HELPER(gvec_vcgd64s)(void *v1, const void *v2, CPUS390XState *env,
351                           uint32_t desc)
352 {
353     const uint8_t erm = extract32(simd_data(desc), 4, 4);
354     const bool XxC = extract32(simd_data(desc), 2, 1);
355 
356     vop64_2(v1, v2, env, true, XxC, erm, vcgd64, GETPC());
357 }
358 
359 static uint64_t vclgd64(uint64_t a, float_status *s)
360 {
361     const uint64_t tmp = float64_to_uint64(a, s);
362 
363     return float64_is_any_nan(a) ? 0 : tmp;
364 }
365 
366 void HELPER(gvec_vclgd64)(void *v1, const void *v2, CPUS390XState *env,
367                           uint32_t desc)
368 {
369     const uint8_t erm = extract32(simd_data(desc), 4, 4);
370     const bool XxC = extract32(simd_data(desc), 2, 1);
371 
372     vop64_2(v1, v2, env, false, XxC, erm, vclgd64, GETPC());
373 }
374 
375 void HELPER(gvec_vclgd64s)(void *v1, const void *v2, CPUS390XState *env,
376                            uint32_t desc)
377 {
378     const uint8_t erm = extract32(simd_data(desc), 4, 4);
379     const bool XxC = extract32(simd_data(desc), 2, 1);
380 
381     vop64_2(v1, v2, env, true, XxC, erm, vclgd64, GETPC());
382 }
383 
384 static uint64_t vfi64(uint64_t a, float_status *s)
385 {
386     return float64_round_to_int(a, s);
387 }
388 
389 void HELPER(gvec_vfi64)(void *v1, const void *v2, CPUS390XState *env,
390                         uint32_t desc)
391 {
392     const uint8_t erm = extract32(simd_data(desc), 4, 4);
393     const bool XxC = extract32(simd_data(desc), 2, 1);
394 
395     vop64_2(v1, v2, env, false, XxC, erm, vfi64, GETPC());
396 }
397 
398 void HELPER(gvec_vfi64s)(void *v1, const void *v2, CPUS390XState *env,
399                          uint32_t desc)
400 {
401     const uint8_t erm = extract32(simd_data(desc), 4, 4);
402     const bool XxC = extract32(simd_data(desc), 2, 1);
403 
404     vop64_2(v1, v2, env, true, XxC, erm, vfi64, GETPC());
405 }
406 
407 static void vfll32(S390Vector *v1, const S390Vector *v2, CPUS390XState *env,
408                    bool s, uintptr_t retaddr)
409 {
410     uint8_t vxc, vec_exc = 0;
411     S390Vector tmp = {};
412     int i;
413 
414     for (i = 0; i < 2; i++) {
415         /* load from even element */
416         const float32 a = s390_vec_read_element32(v2, i * 2);
417         const uint64_t ret = float32_to_float64(a, &env->fpu_status);
418 
419         s390_vec_write_element64(&tmp, i, ret);
420         /* indicate the source element */
421         vxc = check_ieee_exc(env, i * 2, false, &vec_exc);
422         if (s || vxc) {
423             break;
424         }
425     }
426     handle_ieee_exc(env, vxc, vec_exc, retaddr);
427     *v1 = tmp;
428 }
429 
430 void HELPER(gvec_vfll32)(void *v1, const void *v2, CPUS390XState *env,
431                          uint32_t desc)
432 {
433     vfll32(v1, v2, env, false, GETPC());
434 }
435 
436 void HELPER(gvec_vfll32s)(void *v1, const void *v2, CPUS390XState *env,
437                           uint32_t desc)
438 {
439     vfll32(v1, v2, env, true, GETPC());
440 }
441 
442 static void vflr64(S390Vector *v1, const S390Vector *v2, CPUS390XState *env,
443                    bool s, bool XxC, uint8_t erm, uintptr_t retaddr)
444 {
445     uint8_t vxc, vec_exc = 0;
446     S390Vector tmp = {};
447     int i, old_mode;
448 
449     old_mode = s390_swap_bfp_rounding_mode(env, erm);
450     for (i = 0; i < 2; i++) {
451         float64 a = s390_vec_read_element64(v2, i);
452         uint32_t ret = float64_to_float32(a, &env->fpu_status);
453 
454         /* place at even element */
455         s390_vec_write_element32(&tmp, i * 2, ret);
456         /* indicate the source element */
457         vxc = check_ieee_exc(env, i, XxC, &vec_exc);
458         if (s || vxc) {
459             break;
460         }
461     }
462     s390_restore_bfp_rounding_mode(env, old_mode);
463     handle_ieee_exc(env, vxc, vec_exc, retaddr);
464     *v1 = tmp;
465 }
466 
467 void HELPER(gvec_vflr64)(void *v1, const void *v2, CPUS390XState *env,
468                          uint32_t desc)
469 {
470     const uint8_t erm = extract32(simd_data(desc), 4, 4);
471     const bool XxC = extract32(simd_data(desc), 2, 1);
472 
473     vflr64(v1, v2, env, false, XxC, erm, GETPC());
474 }
475 
476 void HELPER(gvec_vflr64s)(void *v1, const void *v2, CPUS390XState *env,
477                           uint32_t desc)
478 {
479     const uint8_t erm = extract32(simd_data(desc), 4, 4);
480     const bool XxC = extract32(simd_data(desc), 2, 1);
481 
482     vflr64(v1, v2, env, true, XxC, erm, GETPC());
483 }
484 
485 static void vfma64(S390Vector *v1, const S390Vector *v2, const S390Vector *v3,
486                    const S390Vector *v4, CPUS390XState *env, bool s, int flags,
487                    uintptr_t retaddr)
488 {
489     uint8_t vxc, vec_exc = 0;
490     S390Vector tmp = {};
491     int i;
492 
493     for (i = 0; i < 2; i++) {
494         const uint64_t a = s390_vec_read_element64(v2, i);
495         const uint64_t b = s390_vec_read_element64(v3, i);
496         const uint64_t c = s390_vec_read_element64(v4, i);
497         uint64_t ret = float64_muladd(a, b, c, flags, &env->fpu_status);
498 
499         s390_vec_write_element64(&tmp, i, ret);
500         vxc = check_ieee_exc(env, i, false, &vec_exc);
501         if (s || vxc) {
502             break;
503         }
504     }
505     handle_ieee_exc(env, vxc, vec_exc, retaddr);
506     *v1 = tmp;
507 }
508 
509 void HELPER(gvec_vfma64)(void *v1, const void *v2, const void *v3,
510                          const void *v4, CPUS390XState *env, uint32_t desc)
511 {
512     vfma64(v1, v2, v3, v4, env, false, 0, GETPC());
513 }
514 
515 void HELPER(gvec_vfma64s)(void *v1, const void *v2, const void *v3,
516                          const void *v4, CPUS390XState *env, uint32_t desc)
517 {
518     vfma64(v1, v2, v3, v4, env, true, 0, GETPC());
519 }
520 
521 void HELPER(gvec_vfms64)(void *v1, const void *v2, const void *v3,
522                          const void *v4, CPUS390XState *env, uint32_t desc)
523 {
524     vfma64(v1, v2, v3, v4, env, false, float_muladd_negate_c, GETPC());
525 }
526 
527 void HELPER(gvec_vfms64s)(void *v1, const void *v2, const void *v3,
528                          const void *v4, CPUS390XState *env, uint32_t desc)
529 {
530     vfma64(v1, v2, v3, v4, env, true, float_muladd_negate_c, GETPC());
531 }
532 
533 static uint64_t vfsq64(uint64_t a, float_status *s)
534 {
535     return float64_sqrt(a, s);
536 }
537 
538 void HELPER(gvec_vfsq64)(void *v1, const void *v2, CPUS390XState *env,
539                          uint32_t desc)
540 {
541     vop64_2(v1, v2, env, false, false, 0, vfsq64, GETPC());
542 }
543 
544 void HELPER(gvec_vfsq64s)(void *v1, const void *v2, CPUS390XState *env,
545                           uint32_t desc)
546 {
547     vop64_2(v1, v2, env, true, false, 0, vfsq64, GETPC());
548 }
549 
550 static int vftci64(S390Vector *v1, const S390Vector *v2, CPUS390XState *env,
551                    bool s, uint16_t i3)
552 {
553     int i, match = 0;
554 
555     for (i = 0; i < 2; i++) {
556         float64 a = s390_vec_read_element64(v2, i);
557 
558         if (float64_dcmask(env, a) & i3) {
559             match++;
560             s390_vec_write_element64(v1, i, -1ull);
561         } else {
562             s390_vec_write_element64(v1, i, 0);
563         }
564         if (s) {
565             break;
566         }
567     }
568 
569     if (match) {
570         return s || match == 2 ? 0 : 1;
571     }
572     return 3;
573 }
574 
575 void HELPER(gvec_vftci64)(void *v1, const void *v2, CPUS390XState *env,
576                           uint32_t desc)
577 {
578     env->cc_op = vftci64(v1, v2, env, false, simd_data(desc));
579 }
580 
581 void HELPER(gvec_vftci64s)(void *v1, const void *v2, CPUS390XState *env,
582                            uint32_t desc)
583 {
584     env->cc_op = vftci64(v1, v2, env, true, simd_data(desc));
585 }
586